Intercom

From both the administrative and user perspective, the ease of use and just overall depth of what you can create with the product is very impressive. It allows a great amount of customer support to be automated and simplify it's delivery via articles and a knowledge base that'll continually grow.

Although it's not the biggest feature, as a user, I love that it's focused on getting you an answer/resolution the quickest way possible given the same entry method. Type "adding users" in an application with Intercom support will quickly both deliver you articles that can potentially solve your problem or will also quickly deploy a CSM to you to answer it directly in case it was a bit more complex.

Best part though is the feedback cycle, you're typing exactly what you want to know into the application and if no articles return: New Content Topic.

Theres really not much. I've run into situations where it was wrongly applied within other organizations and not properly resourced, giving a less than average experience. But that's not as much specific to Intercom themselves.

Given they are the industry leader, it can come at a premium for a larger organizations.

In a few words, using Intercom is such a wholesome experience with zero to non competitor in the market who can compete with his top notch features and constant improvements. There is always something new in the works to make it even more useful.

The overall quality of the SaaS is very good, but the price you have to pay for everyone of the features is a bit too much compared to what is offered from the competition, don't get me wrong, being at the top of the list comes with a hefty price tag.

Easiest support tool to have.
Makes your team very accessible, also makes the support process simple for the end users
Good integrations and useful statistics provided

Pricing - it is not very cheap. Pricing also often changes
Help center tool - it could really use some help and updates
Also, a lot of Add block tools catch Intercom as an ad and blocks it - thus creating inconvenience for end users having to choose between

Integration with communication sources, say you may set up the email to be shown in chat history as a messages.
Embedded chats with history are quite nice, it has both the messages and notes left by the supporting team members to each other. Chat itself works quite good and overall thing of a good quality. Not quite sure this is their own development, but it doesn't really matter.
Webhooks, these one is a good thing to integrate your decision making software with customer lifecycle events, for example to send email when credit card is about to expire, of when customer purchased something few times.
Actions - automated reactions to customer or lead lifecycle events.
Filtered cogorts are called segments in Intercom, they have their own filtering panel which is similar to one that can be found on other products.

Bugs. They are everywhere. Updates may be lost, updates may be rejected by intercom because of server side exceptions, or mysterious thing called "concurrent updates" when there is just a single update.
They have huge API downtimes which can be traced by Intercom's API 5XX responses but technical support always denies the existence of a problem or downtime.
Technical support is one of the worst supports I have ever seen. They know nothing, they do not want to learn, the problem is always on your side even if it is their server who responses with 5XX status.

Intercom is hugely, fabulously overpriced.
On paper Intercom has a set of importers - they are useless, as there are no transformation or calculated fields. Now imagine you need to import hundred of thousands customer profiles from legacy system. Due to absence of data transformation mechanisms you are unable to import them as is and have to resort to preparation-export steps. The problem is that you can not perform more than 85 API requests per minute.
There was batch API but today it is 1) deprecated and 2) counts the record inside the batch by the same 85/min limit.
Sometimes customer profile may just disappear.
Some of integrations provided by Intercom would not work as they have never been tested.
There is no API call to "archive the segment" despite it was proposed few years ago.
Intercoms offers one of the worst client libraries on the whole github and they reject PR's.

I like that we are able to gain insight, offer promos, convert leads, provide support, host a help center, and create unique customer journeys right from within one platform. The Inbox feature is very helpful in providing quick and easy support, especially when using the Intercom mobile app!

There are few things I would consider cons about Intercom. I wish they offered a bit quicker support, as I often wait a day to hear back, but it is a minor detail compared to the value we get from using the platform.